Fluorinated polymer and monomers

ABSTRACT

Disclosed herein is a partially fluorinated polymer containing cyclic units. The polymer is particularly useful in for coatings and encapsulants. Also disclosed herein is the novel monomer from which the polymer is made, and a novel intermediate for that monomer.

This is a division of application Ser. No. 08/169,917, filed Dec. 20,1993, now U.S. Pat. No. 5,336,741.

FIELD OF THE INVENTION

This invention concerns a novel partially fluorinated alkenyl vinylether which can be (co)polymerized to novel polymers containing ringstructures. The polymers are useful for films and coatings. Also claimedis a novel intermediate for making the monomer.

TECHNICAL BACKGROUND

The instant monomer, a partially fluorinated omega-alkenyl vinyl ether,can be polymerized to an uncross-linked (soluble), amorphous polymer.

U.S. Pat. No. 4,897,457 reports that perfluorinated omega-alkenyl vinylethers can be polymerized to polymers that are amorphous and containring structures.

J. E. Fearn, et al., J. Polym. Sci. A-1, volume 4, p. 131-140 (1966) andD. W. Brown et al., J. Polym. Sci. A-2, vol. 7, p. 601-608 (1969)indicate that certain perfluorinated alpha-omega dienes can bepolymerized to soluble ring containing polymers. These polymers are notreported to be crystalline.

U.S. Pat. No. 5,260,492 describes polymers, from partially fluorinatedomega-alkenyl vinyl ethers, which polymers contain cyclic structure(s).The polymers are reported to be uncrosslinked and crystalline.

SUMMARY OF THE INVENTION

This invention concerns a polymer, comprising, the repeat unit ##STR1##or both.

This invention also concerns a compound of the formula R¹ CF₂ CH₂OCF═CFH, wherein R¹ is CF₂ ClCFCl-- or CF₂ ═CF--.

DETAILS OF THE INVENTION

This invention concerns a certain partially fluorinated omega-alkenylvinyl ether and a polymer made by free radical polymerization from thatvinyl ether. The polymer is totally amorphous and is useful wheretransparency and low light scattering are important, such as jacketingfor an optical fiber. The polymer is soluble in common organic solvents,and is therefore particularly suited for films and coatings.

The syntheses of the omega-alkenyl vinyl ether, and its dichloroprecursor are found in Examples 1 and 2.

The free radical (co)polymerization of the fluorinated omega-alkenylvinyl ether can be done by conventional means known to those skilled inthe art of fluoroolefin (including vinyl ethers) polymerization, seeU.S. Pat. No. 4,897,457 and H. F. Mark, et al., Ed., Encyclopedia ofPolymer Science and Engineering, Vol. 16, John Wiley and Sons, New York,1989, p. 577-648, both of which are hereby included by reference. Thepolymerization can be carried out neat, in solvent, or in nonaqueoussuspension, aqueous suspension, or aqueous emulsion. Typical suitablefree radical initiators include bis(perfluoropropionyl) peroxide andbis(4-t-butylcyclohexylperoxy) dicarbonate. Typical (co)polymerizationsare described in Examples 3 and 4.

Suitable comonomers include fluorinated and unfluorinated monomers suchas tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride,perfluoro-(methyl vinyl ether), perfluoro(propyl vinyl ether), methylvinyl ether, propylene, ethylene, chlorotrifluoroethylene, perfluoro(2,2-dimethyl-1,3-dioxole), and CF₂ ═CF(CF₂)_(m) OCF═CF₂ where m is 1, 2or 3. Preferred comonomers are tetrafluoroethylene and perfluoro(propylvinyl ether). Also preferred is the homopolymer of the instantfluorinated omega-alkenyl vinyl ether.

By "comprising" herein, in the claim to polymers containing the ##STR2##repeat units, is meant that the polymer contains these unit(s), and canoptionally contain other units (from comonomers) so as to form acopolymer.

The polymers made herein are useful in molding parts, and in coatingsand encapsulants. They are particularly useful as coatings andencapsulants because even though they may have a high fluorine contentand good thermal stability, they are soluble in organic solvents, suchas ethyl acetate, acetone, tetrahydrofuran and N,N-dimethylformamide.Solutions of the polymers may be used to coat or encapsulate articles inconventional ways.

In the Examples, the following abbreviations are used:

DMF--N,N-dimethylformamide

GC--gas chromatography

GPC--gel permeation chromatography

Mn--number average molecular weight

Mw--weight average molecular weight

TGA--thermogravimetric analysis

EXAMPLE 1 Preparation of CF₂ ClCFClCF₂ CH₂ OCF═CFH

To a stirred solution of 9.0 g (60% dispersion in mineral oil) of NaHand 150 mL of ether was slowly added 30 g of3,4-dichloro-2,2,3,4,4-pentafluorobutanol at 0° C. After the additionwas complete, the reaction mixture was stirred at room temperature for 3hours, and then transferred into a 0.4 L shaker tube. The tube waspurged with N₂ and pressured with 100 g of trifluoroethylene and thenkept at 50° C. for 50 hours. The reaction mixture was quenched with 10mL of methanol and poured into 50 mL of water. The ether layer wasseparated and aqueous layer was extracted with ether. The combined etherlayers were dried over MgSO₄. After evaporation of the ether, theresidue was distilled under reduced pressure to give 20.4 g of material,bp 69°-71° C. 40 mmHg. GC and NMR indicated that the product is an E/Zisomeric mixture in a 3:1 ratio and contained 30% of starting alcohol. ¹H NMR: 6.70 (dd, J=72.9 Hz, J=3.9 Hz, E), 6.50 (dd, J=72.9 Hz, J=13.7Hz, Z) [total 1H], 4.54 (t, J=13.7 Hz, E), 4.41 (t, J=13.6 Hz, Z),[total 2H]. ¹⁹ F NMR: -63.5 to -64.7 (m, 2F), -114.0 to -115.0 (m, 2F),-106.3 (t, J=14.8 Hz, Z), -131.7 (d, J=121.0, E), [total 1F], -131.8 (m,1F), -189.6 (dd, J=71.2 Hz, J=15.7 Hz, Z), -196.5 (dd, J=121.3 Hz,J=73.0 Hz, E) [total 1F]. HRMS: Calcd. for (C₆ H₃ F₇ Cl₂ O+H): 294.9527.Found: 294.9514.

EXAMPLE 2 Preparation of CF₂ ═CFCF₂ CH₂ OCF═CFH

To a stirred solution of 6.5 g of Zn and 15 mL of DMF was added 0.5 mLof 1,2-dibromoethylene at 90° C. After the resulting mixture was stirredfor 20 minutes, 18.0 g of above difluorovinyl ether (Example 1) wasslowly added over 30 minutes at 100° C. After the addition was complete,the reaction mixture was stirred for 1.5 hours. Volatile materials (7.5g) were collected in dry ice-acetone trap under partial vacuum (200-130mmHg). Redistillation gave 5.2 g of desired product as an E/Z isomericmixture in a 3.0:1 ratio, bp 60°-63° C./210 mmHg, 99.8% purity. ¹ H NMR:6.68 (dd, J=73 Hz, J=4.0 Hz, E), 6.46 (dd, J=73 Hz, J=13.7 Hz), [total1H], 4.37 (t, J=11.2 Hz, E), 4.25 (t, J=11.5 Hz, Z), [total 2H]. ¹⁹ FNMR: -92.1 and -92.2 (ddt, J=58.3 Hz, J=36.5 Hz, J=5.5 Hz, 1F), -107.5to -108.5 (m, 1.33F), -111.4 (m, 2F), -131.3 (dd, J=121.9 Hz, J=4.0 Hz,0.66F), -189.7 to -190.5 (m, 1.33F), -196.7 (dd, J=121.9 Hz, J=73 Hz,0.66F). IR: 3140 (w), 2960 (w), 1790 (s), 1750 (s), 1315 (s), 1170 (s),1145 (s), 1065 (s), 1035 (s).

EXAMPLE 3

Homopolymerization of CF₂ ═CFCF₂ CH₂ OCF═CFH

A 25 mL glass ampul fitted with a Teflon® coated stir bar was chargedwith 0.2 mL of 5% of bis(perfluoropropionyl)peroxide in1,1,2-trichlorotrifluoroethane and 1.2 g of the title compound. Theampul was sealed and cooled in a liquid nitrogen bath. After beingevacuated and purged with N₂ alternately six times, contents of thesealed ampul were stirred at 35°-40° C. for 24 hours. The resultingwhite solids were dissolved in ethyl acetate, reprecipitated by additionof methanol containing 10% water and dried under vacuum at 100° C. togive 0.54 g of polymer.

The IR spectrum of this polyer showed no absorption at around 1790 and1750 cm⁻¹ which could be attributed to double bonds in the polymer. ¹ HNMR and ¹⁹ F NMR analysis of this polymer in acetone-d₆ indicated thecyclic structure. IR: 2980 (w), 1470 (w), 1380 (m), 1280 (s), 1250 (s),1120 to 1140 (s). ¹ H NMR (vs. TMS): 5.4 to 5.8 (br, 1H), 4.8 (br, 2H);¹⁹ F NMR (vs. CFCl₃): -110.8 to -121.6 (m, 7F), -179 to -180.5 (m, 1F),-205 (m, 1F).

This polymer was soluble in acetone, ethyl acetate, tetrahydrofuran andDMF, and was insoluble in 1,1,2-trichlorotrifluoroethane, chloroform,toluene, and methanol. The polymer had a glass transition temperature of134°-141° C. It could be obtained as a colorless and transparent thinfilm upon removing solvent from its solution in DMF spread on a glassplate. GPC analysis indicated that M_(w) was 2.2×10⁵ and M_(n) was1.27×104. By TGA the polymer showed 10% weight loss temperatures ofabout 445° C. in nitrogen and 335° C. in air, respectively, when heatedat 20° C./minute.

EXAMPLE 4

Copolymerization of CF₂ ═CFCF₂ CH₂ OCF═CFH with perfluoropropylvinylether (PPVE)

A 25 mL glass ampul fitted with a Teflon® coated stir bar was chargedwith 0.2 mL of 5% of bis (perfluoropropionyl)peroxide in1,1,2-trichlorotrifluoroethane, 1.0 g of CF₂ ═CFCF₂ CH₂ OCF═CFH and 1.0g of PPVE. The ampul was sealed and cooled in a liquid nitrogen bath.After being evacuated and purged with N₂ gas six times, contents of thesealed ampul were stirred at 40° C. for 24 hours. The resulting whitesolids were dissolved in ethyl acetate, reprecipitated by addition ofmethanol containing 10% water and dried under vacuum at 100° C. to give0.81 g of polymer. This polymer was dissolved in acetone-d₆ to measureits ¹⁹ F NMR spectrum, from which the polymer was found to be acopolymer consisting of a unit of the cyclic structure derived from CF₂═CFCF₂ CH₂ OCF═CFH and a unit of the structure derived from PPVE in a94.3 to 5.7 ratio. ¹ H NMR: 5.8 to 5.4 (br, 1H), 4.8 (br, 2H). ¹⁹ F NMR:-81.0 (m, CF₃), -109 to -121.6 (m, CF₂ and CFO), -129.0 (s, CF₂ ofPPVE), -179 to -180.5 (m, CF), -203 to -205 (m, CFH).

The polymer had a glass transition temperature of 128° to 135° C. GPCanalysis indicated that M_(w) was 2.84×10⁵ and M_(n) was 1.84×10⁴. ByTGA the polymer showed 10% weight loss temperatures of about 460° C. innitrogen and 355° C. in air, respectively, when heated at 20° C./minute.

What is claimed is:
 1. A compound of the formula R¹ CF₂ CH₂ OCF═CFH,wherein R¹ is CF₂ ClCFCl-- or CF₂ ═CF--.
 2. The compound as recited inclaim 1 wherein R¹ is CF₂ ClCFCl--.
 3. The compound as recited in claim1 wherein R¹ is CF₂ ═CF--.